The present invention relates to a guidance system and method, and, more particularly, to such a system and method which permits a person whose vision is impaired to continuously know his or her location within an area.
Many different types of guidance systems and aids have been developed and employed for the purpose of guiding or assisting people whose vision is impaired. In the present application, the meaning of impaired vision includes not only a person suffering from a physical or other such disability which results in full or partial blindness, but also a temporary or area restricted vision impairment, such as may be encountered in a low-light environment, for example, in a movie theatre, smoke-filled corridor, or in a building during a power failure.
In the case of a low-light environment, devices such as independently powered emergency lighting and/or chemiluminescent lighting are sometimes employed to assist in properly orienting a person and/or guiding a person through the affected area. Some facilities employ physical structures such as handrails or embossed arrows or the like for this purpose. These devices have not been widely used or generally accepted so that there are many such low-light environment areas or potentially low-light environment areas (i.e., areas susceptible to power failure) which provide no such guidance aids.
Many different types of sensor aids have also been recently developed and produced for persons having a physical, visual impairment resulting in full or partial blindness. Many of the latest innovations are electromechanical in nature and are directed at improving existing aids, including such devices as laser canes. Other such innovations are merely new applications of existing technological devices such as sonic guides. Although many of the newer devices are technologically sound, because of their design, expense and complication, to date, they have not been widely accepted.
Recently, researchers have been examining the utility of tactual stimulation for guidance purposes. One avenue of such tactual stimulation involves the use of a change in the physical features of a floor surface as a cue to warn an individual of imminent danger, such as an obstacle, stairway or the like which is about to be encountered. For example, a generally smooth concrete sidewalk may be modified proximate the curb with a strip of rough surface material, such as by embedding pebbles or stones in the concrete surface, to clearly indicate the location of the curb. A person with impaired vision walking along the sidewalk who strays near the curb will immediately notice the difference in the texture beneath his or her feet and can change direction to avoid entering the street. Similarly, such a rough textured surface may be employed in connection with a pedestrian walkway crossing a street, particularly at an irregularly shaped intersection, again for the purpose of indicating the edge of the walkway to help keep a visually impaired person within the walkway.
While the use of such intermittently placed tactual stimuli for the purpose of delineating the location of obstacles or hazards or for signalling the position of lankmarks and objects has been shown to be effective for these purposes, the strategic placement of such stimuli constitute a very small percentage of the surface area contacted in routine travel by visually impaired persons. The area between these intermittent warning stimuli comprises the vase majority of surface area which has not been previously addressed.
The present invention comprises a bipedal guidance system for a person whose vision is impaired, which employs tactual stimulation over substantially the entire walking surface of a particular area, such as a room, hallway, pathway, intersection or the like. Thus, the entire floor or walking surface contains relevant information. The present invention represents a departure from the simple detection of intermittent gross changes in the walking surface to warn of impending obstacles or to signal landmarks and objects. Unlike the above-discussed prior art, there is no need to seek out a particular pathway, guidestrip or series of intermittent signals or stimuli. A person can proceed at his or her own natural stride and/or pace without having to compensate or adjust to conform to fixed guidestrips or separated cues. Further, unlike current technology, the present invention employs graded tactual stimuli to provide pedestrians with a means to develop spatial discriminations with respect to the area traversed.
The present invention also provides an independent and inconspicuous guidance system which permits a person whose vision is impaired to determine both the spatial dimension of the particular area and his or her location within the area. With the present invention, individuals feel with their feet to detect tactual stimuli over virtually the entire area of a walking surface which can guide them safely and efficiently along the walking surface. The physical changes in the tactual stimulation gradient approximates the functions of changes in visual stimuli for persons without visual impairments. By transposing these relevant stimulus features onto a textual medium, the present invention provides continuous and maximal stimulation. Thus, for example, the present invention provides for safe two-way traffic of persons whose vision is impaired, without interfering with the movement of other people, wheelchairs, etc. within the same area. With the proper training, the bipedal guidance system can supplement or reduce and eventually replace many spatial orientation and mobility functions currently accomplished with the use of a cane, guide dog and other such sensory aids. Since the tactual stimuli employed with the present invention are relatively unobtrusive, the guidance system can be used in areas normally traversed by people whose vision is not impaired and/or people with mobility impairments, without undue interference. The present invention, therefore, has the potential of providing genuine independence for a person whose vision is impaired.